Keith, in TAR1, a team of two men did indeed make it to the final three. However, at the end, they were a full day behind the other two teams. Since then the producers have orchestrated a lot more "bunching" of teams.

I think that two men (Chip and Reichen) also won Amazing Race - but I'm not absolutely sure.

Chip and Reichen did win that Amazing Race.

In reply to "Wednesday"-

My mother and I were considring applying for an upcoming season, once I am done with college. However, if they keep the 4-person format, we don't have any one else we would like to do it with, :(